Gyrotrac HD500 vs. carbide cutter with blades installed.

[Gamma]

For those of you that have used or demo'd a carbide mulching head that has had steel blades installed instead of the normal carbide teeth, how do you think it compares to the Gyrotrac HD500 mulching head or Loftness Timber Axe?

The Gyrotrac head has circular pieces of steel that 'fill in' the space around each blade, from the backside all the way around the rotor drum to the almost the frontside of the same blade. I'm assuming this is to keep the teeth from taking too much of a 'bite' in a tree or log. How much of an advantage is this design feature in the Gyrotrac head? Is it a disadvantage not having this feature in the Loftness Timber Axe or various carbide heads with steel blades installed? Do they take too big of bites not having the spacers?

 

[Terra Firma Scott]

The Timber Ax has a shear bar that adjusts..I believe this is what controls the initial product cut size as the knives pull the material against the bar. I was going to adjust mine to see what it would do..tweak and adjust..The current setting wont allow the drum/knives to bite too much at once...small gap...which in my case may be the best setting since I dont have the big dog machine like most of you mulchers.... If i enlarge the gap, I believe the cut will be larger hence stalling or slowing the drum considerably.. Need to try it and see
Scott-

 

[DirtyWorks]

Hey Gamma, sorry been a little busy lately this is a good thing. About the gyro vs steel modified, I believe, correct me if i'm wrong, that I am the only one on here running modified prototype knives. I do not have a gyrotrac HD500 but I do have aquaintances with one. He ran a head exactly hooked up like mine on his machine and was impressed. The debate may well go on for years to come but here are my thoughts. At a savings of 10-12 grand these heads will stand toe to toe, acre for acre and match chip size and overall performance.
At first you will get stalled out more because, as you stated, the head will take as large a bite as you feed it. As you run it you adjust. Normally with carbide hammers you run aggressively to get all the performance and production you can. It is all in how you run. With knives you do need to let the machine work. Think of it this way if you will. Carbide hammers are like trying to clear land with the wrong side of the axe. It takes a lot of energy (horsepower) to swing it backward and dosent leave a clean cut but the back of the axe will hold up a long time. Now if the person swings the sharpe blade side they will get more done for less energy but the axe will dull a lot faster.
The advantages of knives quickly outweigh the cons.
My next step is to knives with carbide tips
The best of both worlds. 5X the sharp life, repairable, and sharpenable.
All this for a great savings in initial investment. I am now experiencing @45-50 hrs of steel between resharpening. at these hours gyrotracs would be comepletely unserviceable.
Sorry for the rant but then again mabey its all cause I can't afford a gyrotrac? Guess I need to cut another 10 acres this week....

 

[DirtyWorks]

And she cuts better than she looks. I should say he instead of she cause he has BALLS!
If you look close at the left you can see a root that i did not even know was there when i started the head up for the first time. verry clean cut.

 

[deniscimafinc]

Hello Gamma,

The protective discs your refer to in your post is there for two main reasons:
1 - limit size of material being chipped;
2 - protect the blade holders from direct impacts (only the tip of the blade is exposed, more or less);

By limiting the size of the material you chip, you prevent the machine from dying by running to fast in large stumps. And the result finish looks better too.

By protecting the blade holder, you put the "impact relief" on the blade. If you'd hit a hidden rock too hard, you would break the blade only, leaving the blade holder welded on the rotor. Then there's no need to prepare for in-field welding. Just bring a socket wrench to unbolt the broken blade and bolt the new one on.

Also, because the disc is welded behind the blade holder, it adds support to the blade holder. That adds to the strenght of the construction.

By the way, what you see on Gyrotrac "planar heads" were actually developed by DENIS CIMAF Inc. Gyrotrac currently use that patented technology under license. You can see details of the patent on the US Patent and Trademark Office at :
www.uspto.gov

Just search for patent number:
6764035

Ok, enough for now...